Chronic wounds affect approximately 6.5 million Americans and the incidence is expected to rise by 2% annually over the next decade, due to aging population, diabetes, obesity, and late effects of radiation therapy. Among the major chronic wounds are lower extremity ulcers (diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs)), apart from pressure and arterial ulcers. The global wound care market is expected to reach $20.5 billion by 2020 at a cumulative annual growth rate of 8%, and just North America alone to $8.1 billion by 2020. Chronic wounds alone are responsible for over $7 billion/year in annual health care costs worldwide. The United States represents more than half the global market with lower extremity ulcers (DFUs and VLUs) being the most chronic wounds.
Initial management of lower extremity ulcers begins with effective clinical assessment of the wound, diagnostic imaging using duplex ultrasound (to assess vascularity, or extent of blood flow), followed by basic and/or advanced treatments (or therapies) for enhancing effective and rapid wound healing. Healing rate is assessed by wound size measurement and visual assessment for surface epithelization. If treatment extends beyond 4 weeks, re-evaluation of wound and advanced treatment options are considered. While currently available diagnostic tools help direct the treatment approach and assess vascularity (i.e., oxygen-rich blood flow), there is no prognostic imaging tool in the clinic to assess improvement in blood oxygenation and simultaneously take spatial measurements of a target wound.